Heretofore, as treating agents for water/oil repellent treatment or antifouling treatment of clothing, various compositions have been provided depending upon the particular purposes. For work wears such as work clothes, linen such as rental sheets, etc., it has been common to employ a fluorine type SR (soil release) agent which has both water/oil repellency to prevent soiling and SR (soil release) properties whereby any soil attached may readily be removed by cleaning or washing.
For example, there have been proposed a fluorine type antifouling agent containing, as an effective component, a copolymer of a (meth)acrylate containing a polyfluoroalkyl group, a (meth)acrylate containing a polyoxyalkylene chain and a (meth)acrylate containing a blocked isocyanate group (the following Patent Document 1), a fluorine type antifouling agent containing, as an effective component, a copolymer of a (meth)acrylate containing a polyfluoroalkyl group, a (meth)acrylate containing a polyoxyalkylene chain and a (meth)acrylate containing an acetoacetyl group (the following Patent Document 2), etc.
With respect to these treating agents, it has been proposed to use a (meth)acrylate containing an ethylene oxide chain and a propylene oxide chain in the same side chain, as the (meth)acrylate containing an oxyalkylene chain, or to use two components of a (meth)acrylate containing an ethylene oxide chain and a (meth)acrylate containing a propylene oxide chain in combination, whereby better water/oil repellency and antifouling performance can be provided.
However, the polyfluoroalkyl group used in these treating agents mainly has at least 8 carbon atoms. In recent years, from the viewpoint of the influence to the environment, it has been recommended for a compound having a perfluoroalkyl group to have less than 8 carbon atoms in the perfluoroalkyl group.
In the following Patent Document 3, a soil release agent is proposed which contains, as an effective component, a copolymer of a (meth)acrylate containing a perfluoroalkyl group having less than 8 carbon atoms, a (meth)acrylate containing a polyethylene oxide chain and a (meth)acrylate containing a polypropylene oxide chain.
Patent Document 1: Japanese Patent No. 3,320,491
Patent Document 2: Japanese Patent No. 3,820,694
Patent Document 3: WO2005/097851